A large two engine train was crossing America. After they had
gone some
distance one of the engines broke down.

"No problem," the engineer thought, and carried on at half-power.
Further on down the line, the other engine broke down, and the train
came to a standstill. The engineer decided he should inform the
passengers about why the trainhad stopped, and made the following announcement:

"Ladies and gentlemen, I have some good news and some bad news.
The badnews is that both engines have failed, and we will be stuck
here for some time. The good news is that this is a train and not a
plane."